Conventional power generators generate electrical energy by means of induction. Such generators employ a stator core along with a rotor shaft having rotor coils associated therewith to rotate within the stator core in order to convert mechanical energy into electrical energy. The generator rotor conventionally includes a plurality of spaced-apart rotor slots often formed in and extending inwardly from outer peripheries of the rotor, e.g., the rotor body. The rotor slots conventionally have a plurality of electrically-conductive rotor wedges which hold the slot contents, e.g., coils, slot filler, insulating materials, within the slots.
These rotor wedges can have a wide variety of shapes, e.g., a top hat type configuration such as shown in prior art FIG. 1, a Christmas tree type configuration, a dovetail type configuration, or other configurations as understood by those skilled in the art. These shapes often correspond to a mating relationship with grooves or channels formed in opposing side walls of a slot and the upper opening of the slot. Also, these rotor wedges often have a plurality of spaced-apart vertically extending (or rotationally extending when the rotor wedge is positioned within a slot) vent holes formed in and extending through the rotor wedges. Examples of rotor wedges with such vent holes can be seen in U.S. Pat. No. 5,048,177 by Keck et al. titled “Generator Rotor Slot Wedge Tool,” U.S. Pat. No. 5,027,500 by Keck et al. titled “Generator Rotor Slot Wedge Assembly And Disassembly,” and U.S. Pat. No. 5,075,959 by Keck et al. titled “Generator Rotor Slot Wedge Assembly And Disassembly Fixture.” Further, rotor wedges also often have vertically or rotationally extending openings, e.g., for fasteners, formed therein for tightening such wedges such as shown in U.S. Pat. No. 6,218,756 by Gardner et al. titled “Generator Rotor Slot Tightening Method and Associated Apparatus.”
Despite the significant improvement in slot tightening techniques with conventional rotor wedges, there is still a need for power generator efficiency and power output enhancements from the generator, and particularly from the rotor. Accordingly, the burden that the rotor wedges must carry in retaining the contents of the slot includes the mass of the contents of the slot and the rotor wedge itself. For a given slot-wedge configuration, the total burden can be stated as:B=Mass(wedge+slot contents) where B is the total burden. This total burden, however, can reduce or be a limitation on the output from and efficiency of the rotor of a power generator based on the rating, size, and type of rotor.